• 文献标题:   Colossal enhancement of spin-orbit coupling in weakly hydrogenated graphene
  • 文献类型:   Article
  • 作  者:   BALAKRISHNAN J, KOON GKW, JAISWAL M, NETO AHC, OZYILMAZ B
  • 作者关键词:  
  • 出版物名称:   NATURE PHYSICS
  • ISSN:   1745-2473 EI 1745-2481
  • 通讯作者地址:   Natl Univ Singapore
  • 被引频次:   254
  • DOI:   10.1038/nphys2576
  • 出版年:   2013

▎ 摘  要

Graphene's extremely small intrinsic spin-orbit (SO) interaction(1) makes the realization of many interesting phenomena such as topological/quantum spin Hall states(2,3) and the spin Hall effect(4) (SHE) practically impossible. Recently, it was predicted(1,5-7) that the introduction of adatoms in graphene would enhance the SO interaction by the conversion of sp(2) to sp(3) bonds. However, introducing adatoms and yet keeping graphene metallic, that is, without creating electronic (Anderson) localization(8), is experimentally challenging. Here, we show that the controlled addition of small amounts of covalently bonded hydrogen atoms is sufficient to induce a colossal enhancement of the SO interaction by three orders of magnitude. This results in a SHE at zero external magnetic fields at room temperature, with non-local spin signals up to 100 Omega; orders of magnitude larger than in metals(9). The non-local SHE is, further, directly confirmed by Larmor spin-precession measurements. From this and the length dependence of the non-local signal we extract a spin relaxation length of similar to 1 mu m, a spin relaxation time of similar to 90 ps and a SO strength of 2.5 meV.